Kinetics determination of substrate 5.

<p>8325–4 WT and <i>srtA</i> KO strains were incubated in the presence of (A) either 1 mM of substrate <b>1</b> or 250 μM of substrate <b>5</b> until either exponential (4 hrs), post-logarithmic (7 hrs), late exponential (8.5 hrs) or late stationary phase (24 hrs) in LB medium. The mean fluorescence of substrate <b>1</b> and substrate <b>5</b> is depicted on y-axis. (B) Washed and diluted (OD_600nm 0.5) late stationary grown WT and <i>srtA</i> KO bacteria were incubated with either 10 μM, 100 μM, 250 μM, 500 μM or 1 mM substrate <b>1</b> or substrate <b>5</b> in SrtA buffer during 17 hrs. The mean fluorescence was determined by FACS. The signal obtained with substrate <b>1</b> at 1 mM after 24 hrs of incubation was significantly lower than the signal obtained with substrate <b>5</b> at 250 μM after 24 hrs (P < 0.001). Substrate <b>5</b> signals at time points 4 hrs, 7 hrs and 8 hrs were all significantly lower in comparison to the signal obtained with the same substrate at 24 hrs time point at 250 μM (P < 0.001).